Most American families begin co-sleeping when their babies are first born, most of those families transition the babies to their own room by the time he or she is six months old. But a new study suggests something different.

The study by the Penn State researchers suggests that recent trends and popular advice that asks new moms not to sleep with their babies may make mothers who do choose to co-sleep with their infants more likely to feel depressed or judged. They more likely to be worried about their babies’ sleep and think their decisions were being criticized.

Scientists analyzed sleeping patterns of almost 103 mothers and feelings about sleep for the first year of their babies’ lives.

Douglas Teti, department head and professor of human development and family studies, Penn State, said that regardless of current parenting trends, it’s important to find a sleep arrangement that works for everyone in the family.

“In other parts of the world, co-sleeping is considered normal, while here in the U.S., it tends to be frowned upon. Co-sleeping, as long as it’s done safely, is fine as long as both parents are on board with it. If it’s working for everyone, and everyone is okay with it, then co-sleeping is a perfectly acceptable option.”

“We found that about 73 percent of families co-slept at the one-month point. That dropped to about 50 percent by three months, and by six months, it was down to about 25 percent. Most babies that were in co-sleeping arrangements, in the beginning, were moved out into solitary sleep by six months.”

Scientists also discovered that the persistent co-sleepers — the moms that were still co-sleeping after six months — were the ones who seemed to get the most criticism. Participants also reported greater levels of worry about their baby’s sleep, which makes sense when you’re getting criticized for something that people are saying you shouldn’t be doing, that raises self-doubt.

The study that distributed in the journal Infant and Child Development, particularly is not about whether co-sleeping is good or bad, instead of about the importance of finding a sleep arrangement that works well.

Teti said, “If you’re going to co-sleep, you have to make sure both people in the partnership have talked it through and both people are in sync with what they want to do. If not, that’s when criticism and arguments can happen, and possibly spill over into the relationship with a child. So you want to avoid that. You need to make sure you have time with your partner, as well.”

“Even when co-sleeping works well, it can still cause more loss of sleep for the parents than if the baby slept in its own room.”

“If you co-sleep, it is going to disrupt your sleep, and probably Mom’s sleep more than Dad’s. So this is something to be careful with if you’re not good with chronic sleep debt. Co-sleeping needs to work well for everyone, and that includes getting adequate sleep. To be the best parent you can be, you have to take care of yourself, and your child benefits as a result.”